package com.lili.filter;


import com.lili.config.Constant;
import com.lili.exception.QhException;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.web.filter.AccessControlFilter;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Slf4j
public class JWTFilter extends AccessControlFilter {

    private Constant constant;


    public JWTFilter(Constant constant) {
        this.constant = constant;
    }

//    /**
//     * 判断用户是否想要登入。
//     * 检测header里面是否包含Authorization字段即可
//     */
//    @Override
//    protected boolean isLoginAttempt(ServletRequest request, ServletResponse response) {
//        HttpServletRequest req = (HttpServletRequest) request;
//        String authorization = req.getHeader("token");
//        return authorization != null;
//    }

    /**
     *
     */
//    @Override
//    protected boolean executeLogin(ServletRequest request, ServletResponse response) throws Exception {
//
//    }

    /**
     * 这里我们详细说明下为什么最终返回的都是true，即允许访问
     * 例如我们提供一个地址 GET /article
     * 登入用户和游客看到的内容是不同的
     * 如果在这里返回了false，请求会被直接拦截，用户看不到任何东西
     * 所以我们在这里返回true，Controller中可以通过 subject.isAuthenticated() 来判断用户是否登入
     * 如果有些资源只有登入用户才能访问，我们只需要在方法上面加上 @RequiresAuthentication 注解即可
     * 但是这样做有一个缺点，就是不能够对GET,POST等请求进行分别过滤鉴权(因为我们重写了官方的方法)，但实际上对应用影响不大
     */
    @Override
    protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) {
        return false;
    }

    @Override
    protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        String requestURI = httpServletRequest.getRequestURI();
        String token = httpServletRequest.getHeader(constant.getTokenHeader());
        if (StringUtils.isBlank(token)) {
            httpServletRequest.getRequestDispatcher(constant.getTokenIsNull()).forward(request, response);
            return false;
        }
        JwtToken jwtToken = new JwtToken(token);
        // 提交给realm进行登入，如果错误他会抛出异常并被捕获
        try {
            getSubject(request, response).login(jwtToken);
        } catch (Exception e) {
            httpServletRequest.getRequestDispatcher(constant.getTokenValidate()).forward(request, response);
            return false;
        }
        // 如果没有抛出异常则代表登入成功，返回true
        return true;
    }

    /**
     * 对跨域提供支持
     */
    @Override
    protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
        log.info("-------------跨域-----------------");
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        httpServletResponse.setHeader("Access-control-Allow-Origin", httpServletRequest.getHeader("Origin"));
        httpServletResponse.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE");
        httpServletResponse.setHeader("Access-Control-Allow-Headers", httpServletRequest.getHeader("x-requested-with"));
        httpServletResponse.setHeader("Access-Control-Allow-Credentials","true");
        // 跨域时会首先发送一个option请求，这里我们给option请求直接返回正常状态
        if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())) {
            log.info("-------------跨域1-----------------");
            httpServletResponse.setStatus(HttpStatus.OK.value());
            return false;
        }
        return super.preHandle(request, response);
    }
}
